How Does the "Binding-Change Model" for Synthesis and Hydrolysis of ATP

Multiple Choice

How does the "binding-change model" for synthesis and hydrolysis of ATP in the inner mitochondrial membrane work? ?

A) "Flipping" of orientation of F1Fo-ATP synthase in the membrane
B) A one-step rotation of 180o
C) Change in the binding constant for ATP on the T subunit
D) Conformation change of the b subunit resulting in release of protons
E) Rotation of the g subunit in 120o steps